The building is infested with bloatflies and bloodbugs. The walls and floors have numerous holes, allowing the insects to travel easily between floors and sections in ways that humans cannot always follow. There are three main sections of the building, and getting between them can require leaving the building and going around the outside: the entrance, a "left" section with access to the upper floor with the locked lab behind a terminal, and the "right" section allowing access to the basement and storage room behind an Expert level locked door. It is possible to drop through the floor of the upper section to bypass the locked door, and in the basement, a password can be found to bypass the terminal and reach the lab.
A high level infected bloodbug guards the basement section and can be difficult for a lower level player character to defeat. Apart from the bloodbug, the building contains a large number of blood packs in the basement.
- Massachusetts Surgical Journal issue #4 - On the second floor, in the room behind the security door. The door can only be opened through the Advanced-locked terminal.
- A large number of blood packs (20+) can be found in the basement.
- Syringer rifle - In the basement.
- Three blood clinic keys - One is on a desk in a small room on the second floor. Another is on the ground floor next to a corpse by the southwest side door entrance (on the inside of the building). A third key can be found in the basement on a desk in the room before the lab/blood storage room. Opens the outside door and the safe in the lab.
- Blood clinic password - Inside the exam room terminal on the ground floor close to the southwest side door entrance. Opens locked the lab room.
- South of the clinic is a group of warehouses and the eastern-most one contains a partially complete leveled set of power armor. This warehouse also contains four power armor stations.
- There is a little background on the last general of Fort Hagen here.
- This is a possible location during the quest Quartermastery given to the player character by Scribe Haylen.
- If the player character has MacCready as a companion, he will comment on the age and untrustworthiness of blood packs that have been sitting around for over 200 years.
- If the player character has Nick Valentine as a companion, he will comment that the basement is a "bloodbug paradise."
The Greater Mass blood clinic appears only in Fallout 4.
PC There may be a glitched blue door on the first floor that cannot be interacted with, however the player can pass through it.[verified]